Methods and devices for CEC propagation control

ABSTRACT

A CEC propagation control function, operated by a manipulating switch coupled to a first, second, and third HDMI-CEC devices, enables the manipulating switch to receive a CEC block from the first HDMI-CEC device, pass the received CEC block to the second HDMI-CEC device, and prevent the third HDMI-CEC device from receiving the CEC block, although the manipulating switch is coupled to the third HDMI-CEC device. The manipulating switch may also be implemented as a network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application also claims the benefit of U.S. Provisional PatentApplication No. 61/056,432, filed on May 27, 2008, incorporated hereinby reference.

BACKGROUND

The HDMI™ (High-Definition Multimedia Interface) standard, of the HDMIconsortium, is a digital interface for audio and video signals. HDMI-CECrefers to an HDMI device that supports CEC (Consumer ElectronicsControl). HDMI-CEC devices enable a user to manage a plurality ofsources connected via HDMI with no special programming needed and to runoperations such as ‘one touch play’. Using HDMI-CEC, the user may, forexample, use one remote control to turn on the TV, DVD, and receiver atthe same time, and to adjust the system volume using one button.

The HDMI-CEC protocol uses a one-wire shared bus that includes automaticmechanisms for logical address allocation based on product type,arbitration, retransmission, broadcasting, and switching control.Operation code (opcode) supports both device specific and generalfeatures. CEC devices have both physical and logical addresses.Normally, upon hot-plugging, each CEC source device obtains a physicaladdress by reading the EDID of the display device to which it isattached.

In some embodiments, an HDMI-CEC message, shortly referred to as “CECmessage”, includes the following CEC blocks: a special start ‘bit’, aheader block containing source and destination addresses, a first datablock containing optional opcode, and a second data block containingoptional operands specific to the opcode. The maximum CEC message size(header block plus opcode block plus operand blocks) is 16*10 bits. EachCEC block includes 8 bits of data, one End-Of-Message (EOM) bit, and oneacknowledge (ACK) bit transmitted by the receiver. A CEC messageincludes a series of CEC blocks wherein only the EOM bit of the lastblock in the message is on. Each CEC message starts with a block having4 bits of source address (also referred to as nibble), 4 bits ofdestination address, an EOM bit, and an ACK bit. A polling messageincludes the same source and destination addresses with the EOM bit on.

CEC includes an option for customized commands. This enables differentvendors to create CEC based networks between products of the specificvendor. Examples of such modified CEC base networks include: Anynet(Samsung), Aquos Link (Sharp), BRAVIA Theatre Sync (Sony), Regza Link(Toshiba), RIHD (Onkyo), Simplink (LG), Viera Link/EZ-Sync(Panasonic/JVC), Easylink (Philips) and NetCommand for HDMI(Mitsubishi).

BRIEF SUMMARY

In one embodiment, a method including: receiving a CEC block which wasinitiated by a first HDMI-CEC device; passing the received CEC block toa second HDMI-CEC device; and preventing a third HDMI-CEC device fromreceiving the CEC block.

In one embodiment, a method including: dividing a plurality of devicesinto at least a first HDMI-CEC cluster tree coupled to a first displaydevice, and a second HDMI-CEC cluster tree coupled to a second displaydevice, wherein the HDMI-CEC cluster trees partially overlap; receivinga first CEC block which was initiated by the first HDMI-CEC clustertree; passing the first CEC block to the first display device, and notpassing the first CEC block to the second display device.

In one embodiment, a device including at least one HDMI-CEC input portand at least two HDMI-CEC output ports; the device is capable ofcontrolling the propagation of CEC messages between its various HDMI-CECports; whereby some of the CEC messages are forwarded between some ofthe HDMI-CEC ports, and some of the CEC messages are prevented frombeing forwarded between some of the HDMI-CEC ports.

In one embodiment, a device including: means for receiving a CEC blockwhich was initiated by a first HDMI-CEC device; and means for passingthe received CEC block to a second HDMI-CEC device and preventing athird HDMI-CEC device from receiving the CEC block.

Implementations of the disclosed embodiments involve performing orcompleting selected tasks or steps manually, semi-automatically, fullyautomatically, and/or a combination thereof. Moreover, depending uponactual instrumentation and/or equipment used for implementing thedisclosed embodiments, several embodiments could be achieved byhardware, by software, by firmware, or a combination thereof. Inparticular, with hardware, embodiments of the invention could exist byvariations in the physical structure. Additionally, or alternatively,with software, selected functions of the invention could be performed bya data processor, such as a computing platform, executing a softwareinstructions or protocols using any suitable computer operating system.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present invention are herein described, by way ofexample only, with reference to the accompanying drawings. No attempt ismade to show structural details of the embodiments in more detail thanis necessary for a fundamental understanding of the embodiments. In thedrawings:

The embodiments of the present invention are herein described, by way ofexample only, with reference to the accompanying drawings. No attempt ismade to show structural details of the embodiments in more detail thanis necessary for a fundamental understanding of the embodiments. In thedrawings:

FIG. 1A illustrates a multi display network in accordance with oneembodiment of the invention;

FIG. 1B illustrates a multi port display device in accordance with oneembodiment of the invention;

FIG. 1C illustrates a manipulating switch inside a display device inaccordance with one embodiment of the invention;

FIG. 2 illustrates a multi port display device in accordance with oneembodiment of the invention;

FIG. 3 illustrates a multi stream network in accordance with oneembodiment of the invention;

FIG. 4 illustrates a multi stream network in accordance with oneembodiment of the invention;

FIG. 5A illustrates a daisy chain in accordance with one embodiment ofthe invention;

FIG. 5B illustrates a multi stream manipulating switch inside a sourcedevice in accordance with one embodiment of the invention;

FIG. 5C illustrates a multi stream manipulating switch inside a sourcedevice in accordance with one embodiment of the invention;

FIG. 5D illustrates a multi stream network in accordance with oneembodiment of the invention;

FIG. 5E illustrates a multi stream manipulating switch inside a sourcedevice in accordance with one embodiment of the invention;

FIGS. 6A-C illustrate HDMI-CEC network views in accordance with oneembodiment of the invention;

FIG. 7 illustrates a multi display network in accordance with oneembodiment of the invention;

FIG. 8 illustrates a multi display network in accordance with oneembodiment of the invention;

FIG. 9 illustrates a multi display network in accordance with oneembodiment of the invention;

FIG. 10 illustrates a manipulating switch in accordance with oneembodiment of the invention;

FIGS. 11A-11B illustrate symmetric communication channels in accordancewith one embodiment of the invention;

FIG. 12 is a flow diagram of one method in accordance with oneembodiment of the invention;

FIG. 13 is a flow diagram of a routing method in accordance with oneembodiment of the invention;

FIG. 14 is a flow diagram of an emulating method in accordance with oneembodiment of the invention;

FIG. 15 is a flow diagram of a menu creation method in accordance withone embodiment of the invention;

FIG. 16 is a flow diagram of a menu creation method in accordance withone embodiment of the invention;

FIG. 17 is a flow diagram of a propagation control method in accordancewith one embodiment of the invention;

FIG. 18 is a flow diagram of a propagation control method in accordancewith one embodiment of the invention;

FIG. 19 is a flow diagram of a CEC on the fly modification method inaccordance with one embodiment of the invention;

FIG. 20 is a flow diagram of a CEC block termination method inaccordance with one embodiment of the invention;

FIG. 21 is a flow diagram of a method in accordance with one embodimentof the invention;

FIG. 22 is a flow diagram of an addresses allocation method inaccordance with one embodiment of the invention;

FIG. 23 is a flow diagram of a logical addresses acquiring method inaccordance with one embodiment of the invention;

FIG. 24 is a flow diagram of a logical addresses acquiring method inaccordance with one embodiment of the invention; and

FIG. 25 is a flow diagram of a physical addresses assignment method inaccordance with one embodiment of the invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth.However, the embodiments of the invention may be practiced without thesespecific details. In other instances, well-known hardware, software,materials, structures and techniques have not been shown in detail inorder not to obscure the understanding of this description. In thisdescription, references to “one embodiment” or “an embodiment” mean thatthe feature being referred to is included in at least one embodiment ofthe invention. Moreover, separate references to “one embodiment” in thisdescription do not necessarily refer to the same embodiment. Illustratedembodiments are not mutually exclusive, unless so stated and except aswill be readily apparent to those of ordinary skill in the art. Thus,the invention may include any variety of combinations and/orintegrations of the embodiments described herein. Also herein, flowdiagrams illustrate non-limiting embodiment examples of the methods, andblock diagrams illustrate non-limiting embodiment examples of thedevices. Some flow diagrams operations are described with reference tothe embodiments illustrated by the block diagrams. However, the methodsof the flow diagrams could be performed by embodiments of the inventionother than those discussed with reference to the block diagrams, andembodiments discussed with reference to the block diagrams could performoperations different from those discussed with reference to the flowdiagrams. Moreover, although the flow diagrams may depict serialoperations, certain embodiments could perform certain operations inparallel and/or in different orders from those depicted. Moreover, theuse of repeated reference numerals and/or letters in the text and/ordrawings is for the purpose of simplicity and clarity and does not initself dictate a relationship between the various embodiments and/orconfigurations discussed.

In the following description, numerous specific details are set forth.However, the embodiments of the invention may be practiced without thesespecific details. In other instances, well-known hardware, software,materials, structures and techniques have not been shown in detail inorder not to obscure the understanding of this description. In thisdescription, references to “one embodiment” or “an embodiment” mean thatthe feature being referred to is included in at least one embodiment ofthe invention. Moreover, separate references to “one embodiment” in thisdescription do not necessarily refer to the same embodiment. Illustratedembodiments are not mutually exclusive, unless so stated and except aswill be readily apparent to those of ordinary skill in the art. Thus,the invention may include any variety of combinations and/orintegrations of the embodiments described herein. Also herein, flowdiagrams illustrate non-limiting embodiment examples of the methods, andblock diagrams illustrate non-limiting embodiment examples of thedevices. Some operations in the flow diagrams may be described withreference to the embodiments illustrated by the block diagrams. However,the methods of the flow diagrams could be performed by embodiments ofthe invention other than those discussed with reference to the blockdiagrams, and embodiments discussed with reference to the block diagramscould perform operations different from those discussed with referenceto the flow diagrams. Moreover, although the flow diagrams may depictserial operations, certain embodiments could perform certain operationsin parallel and/or in different orders from those depicted. Moreover,the use of repeated reference numerals and/or letters in the text and/ordrawings is for the purpose of simplicity and clarity and does not initself dictate a relationship between the various embodiments and/orconfigurations discussed.

DVI™ (Digital Visual Interface) is a video interface standard designedby the Digital Display Working Group consortium. HDMI™ (High-DefinitionMultimedia Interface) is a digital interface for audio and video signalsdesigned by the HDMI consortium. DisplayPort™ is a digital displayinterface standard put forth by the Video Electronics StandardsAssociation (VESA)™.

Conventional CEC networks assume a network topology including only onedisplay device. A display device may be any kind of video display,television, or projector. Some of the following embodiments discuss theoperation of novel methods and systems for utilizing HDMI-CEC in anetwork including more than one display device and novel methods andsystems for multi-display networks supporting HDMI-CEC. The embodimentsmay operate with standard HDMI-CEC devices and/or with partiallycompatible devices.

An HDMI-CEC input port is associated with an “HDMI-CEC cluster tree”which includes all the upstream devices having HDMI physical paths tothat HDMI-CEC input port. Herein, the upstream direction is from a sinkdevice to a source device, and the downstream direction is from a sourcedevice to a sink device.

The term “HDMI-CEC network view” includes the network topology and thelinkage between HDMI physical addresses and CEC logical addresses asexposed to a device through the CEC <report physical address> messagesthat it receives. It is to be understood that the “HDMI-CEC clustertree” represents the actual physical topology while the “HDMI-CECnetwork view” may be manipulated, for example, by a manipulating switchas described below. The HDMI-CEC network view of device ‘X’ enablesdevice ‘X’ to communicate with the various devices available in itsHDMI-CEC network view.

In some of the embodiments, “manipulating switch” denotes a componentcomprising at least one input port supporting HDMI-CEC and at least twooutput ports supporting HDMI-CEC transactions. A manipulating switch mayalso be any component comprising at least one input and at least twooutputs which capable of delivering HDMI-CEC data. A manipulating switchmay utilize any physical transmission that can be converted to HDMI-CEC.Optionally, the manipulating switch may be located within or integratedwith one of the HDMI-CEC source devices. Optionally, the manipulatingswitch may be located within or integrated with one of the HDMI-CECdisplay devices. The manipulating switch may be implemented as a singlecomponent. Alternatively, the manipulating switch may be implemented astwo or more interconnected components, optionally forming a clusterand/or network, whereby the described functionality of the manipulatingswitch may refer to the functionality accomplished by a part or thewhole of the cluster and/or network. FIG. 3 illustrates a manipulatingswitch 41 representing two or more components forming the manipulatingswitch functionality together.

It is to be understood that “HDMI-CEC cluster tree” may refer to anentire network or refer just to a sub-network. Referring to FIG. 1A asan example, in one case, source devices 13-17 form a first HDMI-CECcluster tree coupled to display device 21, and the same source devices13-17 form a second HDMI-CEC cluster tree coupled to display device 22.In another example, display device 21 and source devices 13-17 form afirst HDMI-CEC cluster tree, and display device 22 and source devices13-17 form a second HDMI-CEC cluster tree. The manipulating switch 23may or may not be regarded as included in one or more of the HDMI-CECcluster trees.

Multiple Display Network Supporting HDMI-CEC

In prior art HDMI-CEC devices every CEC message is received by alldevices connected to the HDMI-CEC cluster tree and only one output portmay be connected to the HDMI-CEC cluster tree.

FIG. 1A illustrates one embodiment of a manipulating switch 23 thatincludes logic that enables a plurality of HDMI-CEC display devices (21,22) to control an HDMI-CEC cluster tree, comprised of standard HDMI-CECsources (13, 14, 16, 17) and standard HDMI-CEC switch 15.

The manipulating switch 23 dynamically manipulates the HDMI-CEC networkviews, such that when none of the source devices is active, each displaydevice may control all source devices. And when a first display devicecommunicates with a first source device using HDMI-CEC, the seconddisplay device can still communicate with the other source device usingHDMI-CEC. For example, when none of the source devices is active,display device 21 may control, through its CEC bus, source devices 13,14, 16, and 17 and switches 23 and 15. Display device 22 may alsocontrol, through its CEC bus, the same source devices 13, 14, 16, and 17and switches 23 and 15. When display device 21 activates source device16, the manipulating switch 23 manipulates the HDMI-CEC network view ofdisplay device 22 to reflect only source devices 13 and 14. Sourcedevice 17 is also erased from the HDMI-CEC network view of displaydevice 22 because it is connected though HDMI link 23 c which is alreadyused by source device 16.

FIG. 12 is a flow diagram illustrating one method comprising thefollowing steps: In step 120, manipulating HDMI-CEC messages transmittedover a network comprising at least two HDMI-CEC display devices withtheir associated at least two HDMI-CEC cluster trees that at leastpartially overlap. And in step 121, enabling each of the HDMI-CECdisplay devices to communicate using HDMI-CEC with its associatedHDMI-CEC cluster tree according to its current HDMI-CEC network view.

FIGS. 1B-1C illustrate one embodiment wherein the manipulating switch 1c 1 is located within the display device 1 b 1. The manipulating switch1 c 1 includes logic that enables a plurality of HDMI-CEC displaydevices (1 b 1, 1 b 3) to control an HDMI-CEC cluster tree, comprised ofstandard HDMI-CEC sources (13, 14). The embodiment illustrated by FIG.1B enables a user to chain two or more display devices such that whennone of the source devices is active, each display device may controlall source devices, and when a first display device communicates with afirst source device using HDMI-CEC, the second display device can stillcommunicate with the second source device using HDMI-CEC.

FIG. 2 illustrates one embodiment of a display device with amanipulating switch 12 that includes logic for controlling overlappingor partially overlapping HDMI-CEC networks. By using the manipulatingswitch 12, and assuming that the CEC buses of 11 a and 11 b are notphysically connected, both HDMI-CEC ports (11 a, 11 b) may control theHDMI-CEC sources (13, 14, 16, 17). The HDMI-CEC ports (11 a, 11 b) maybe coupled to a standard HDMI-CEC display device 11 as illustrated. Inthe specific non-limiting example of FIG. 2, the manipulating switch 12resides within a display box 10 (such as a television, a monitor or aprojector), but it is to be understood that the manipulating switch 12may reside within any other display device, source device, or as astand-alone device. The manipulating switch 12 selects and manipulatesthe data to be transmitted over the different HDMI-CEC networksconnected to HDMI-CEC ports 11 a and 11 b.

FIG. 13 is a flow diagram illustrating one method for enablingpicture-in-picture in a display device comprising two HDMI-CEC inputports, each of the HDMI-CEC input ports associated with an HDMI-CECcluster tree, and the HDMI-CEC cluster trees at least partiallyoverlapping, the method comprising the following steps: In step 130,defining an HDMI-CEC network view for each HDMI-CEC input port. In step131, controlling the HDMI-CEC messages transmitted between each HDMI-CECinput port of the HDMI-CEC display device and its HDMI-CEC cluster tree.In step 132, controlling the HDMI-CEC messages transmitted between theHDMI-CEC cluster trees. And in step 133, enabling selecting which of theHDMI-CEC source devices to route to which of the HDMI-CEC input portsusing HDMI-CEC messages.

Referring again to FIG. 2, the manipulating switch 12 includes logicthat enables it to communicate with source devices 13 and 14, and withsource devices 16 and 17 through switch 15, using HDMI-CEC, and stilloutput one or more pictures through ports 11 a and 11 b. This capabilityenables the display device 11 to have, for example, a picture-in-picturefeature, while it is possible to control each picture's source throughthe HDMI-CEC network view. It may also be possible to operate all thesources (13, 14, 16, 17), using the display's remote control, throughstandard HDMI-CEC, while having the picture-in-picture feature.

In one embodiment, the physical addresses, and optionally the logicaladdresses, of the HDMI-CEC network are approximately duplicated by themanipulating switch 12, such that the display device 11 is able tocontrol sources (13, 14, 16, and 17) either through HDMI-CEC port 11 aor through HDMI-CEC port 11 b.

In one embodiment, the manipulating switch 12 transmits some databetween the two HDMI-CEC networks. It is possible to control what datawill be transferred between the HDMI-CEC cluster trees and when.

Operating the Video Network

Prior art HDMI-CEC networks having one display device enable the userto: (i) operate the HDMI-CEC cluster tree using a display device,optionally utilizing the set-stream-path message, and (ii) operate theHDMI-CEC cluster tree using a source device, optionally utilizing theone touch play feature.

In one embodiment, at least one source device is connected through atleast one manipulating switch to at least two display devices, and auser operates the HDMI-CEC network through a display device utilizingthe set-stream-path message. The display device is able to operate therequired source device using the standard set-stream-path messagebecause the manipulating switch makes each display device believe it isconnected to a standard HDMI-CEC network having one display device.

In one embodiment, at least one source device is connected through atleast one manipulating switch to at least two display devices, and auser operates the HDMI-CEC network through a source device utilizing theone touch play feature. In this embodiment, when a source deviceactivates a display device, for example, by utilizing the ‘one-touchplay’ CEC feature, for example as described in HDMI spec 1.3 paragraph“CEC 13.1 One Touch Play”, the manipulating switch should select whichof the available display devices to connect with the source device. Thelogic for selecting the display device to be connected to the sourcedevice may be predefined, dynamically selected, and/or manuallyselected.

For example, the display device on which the content is to be displayedmay be selected according to one of the following non-limiting examples:displaying the content on a display device that is defined as theprimary display device; displaying the content on a display device thatis already active; or displaying the content on a display device that isnot active.

Referring again to FIG. 1A as an example, if source 16 is operating a‘one-touch play’ while display device 21 plays content from sourcedevice 13, manipulating switch 23 may connect source device 16, insteadof source device 13, to display device 21; or connect source device 16to display device 22; or display a menu on display device 21 and/or ondisplay device 22 in order to enable the user to select the desireddisplay device; or connect source device 16 to the display device it waslast connected to; or operate according to any other reasonable logic.

In one embodiment, when the user tries to operate the HDMI-CEC clustertree from the source device, optionally using the one touch playfeature, the manipulating switch takes over and the HDMI-CEC clustertree is operated from the switch as discussed in the next paragraphs. Inother words, operation from a source device may cause operation from themanipulating switch.

In one embodiment, at least one source device is connected through atleast one manipulating switch to at least two display devices, and auser operates the network, which supports HDMI-CEC, through amanipulating switch that performs one or more of the followingoperations: (i) communicating with the various HDMI devices using theHDMI-CEC protocol, including spoofing when needed and as explainedbelow, (ii) creating a control menu, which includes the display devices,and (iii) sending the control menu to at least one of the displaydevices for displaying.

Optionally, the user operates the control menu, created by themanipulating switch, through the remote control of the manipulatingswitch. Alternatively, the user operates the control menu, created bythe manipulating switch, through any other appropriate means such as amultifunctional remote control communicating with the manipulatingswitch, or though the remote control of one of the display devices,wherein the display device forwards the user's selections to themanipulating switch. The display device may forward the user'sselections to the manipulating switch directly or following amanipulation by the manipulating switch. One example of such amanipulation is when the manipulating switch emulates a source devicethat displays its menu on the display device using CEC availablemechanisms for displaying menu and retrieves remote control actions.Examples of such CEC mechanisms are described in HDMI specification 1.3paragraph “CEC 13.12 Device Menu Control” and include messages such as<User Control Pressed>, <User Control Released>, <Menu Request>, or<Menu Status>.

In one embodiment, in order to operate the HDMI-CEC cluster tree throughthe manipulating switch, the manipulating switch supplies the user withthe devices available in the manipulated HDMI-CEC cluster tree (i.e. notbounded by the standard CEC rules).

FIG. 15 is a flow diagram illustrating one method for operating anetwork comprising at least two HDMI-CEC display devices with theirassociated at least two HDMI-CEC cluster trees that at least partiallyoverlap, comprising the following steps: In step 150, communicating withthe various HDMI-CEC cluster trees using HDMI-CEC. In step 151, creatinga control menu which comprises the HDMI-CEC display devices. In step152, sending the control menu to at least one of the HDMI-CEC displaydevices for display. And in step 153, operating the control menuaccording to a user's selection.

FIG. 16 is a flow diagram illustrating one method for operating anetwork comprising at least two HDMI-CEC display devices with theirassociated at least two HDMI-CEC cluster trees that at least partiallyoverlap, comprising: In step 160, communicating with the variousHDMI-CEC cluster trees using HDMI-CEC. In step 161, creating a controlmenu for each of the HDMI-CEC display devices. In step 162, sending thecontrol menus to the HDMI-CEC display devices for display. In optionalstep 163, operating each control menu by a remote control of theHDMI-CEC display device on which it is displayed. And in optional step164, forwarding the user's selections from the HDMI-CEC display deviceto a manipulating switch.

Multi-Stream Channel Supporting CEC

Utilizing a Multi-Stream Channel Within an HDMI-CEC cluster tree.

Standard HDMI interface supports only one stream. A channel that iscapable of transferring more than one HDMI stream is referred to hereinas a multi-stream channel supporting HDMI-CEC. In some embodiments, themulti-stream channel supporting HDMI-CEC may be coupled to two or moreHDMI output ports and therefore is somehow similar to a device havingmultiple HDMI inputs and multiple HDMI outputs.

A multi-stream manipulating switch refers to a switch that supports atleast one multi stream channel. In one embodiment, the multi-streammanipulating switch is capable of manipulating at least some of the HDMIand CEC control transactions. A source device supporting a multi-streamdaisy chain is referred to herein as a source device supportingmulti-stream.

In one embodiment, one or more multi-stream channel supporting HDMI-CECare embedded within an HDMI-CEC network, or within a network that iscompatible or partially compatible with HDMI-CEC. As a result of usingthe multi-stream channel, it is possible to operate more than one sourcedevice connected to the HDMI-CEC cluster tree spanned by themulti-stream channel. Moreover, the system has to manipulate theHDMI-CEC cluster trees connected to the different display devices inorder to be able to operate the source devices using CEC messages.

FIG. 3 illustrates one embodiment of a multi-display network supportingHDMI-CEC with a multi-stream channel 41 c. The display devices (21, 22)are connected to multi-stream manipulating switch 41 that is connectedto multi-stream manipulating switch 42 through a multi-stream channelsupporting HDMI-CEC 41 c. In the illustrated embodiment, manipulatingswitch 41 is implemented as two or more interconnected components,optionally forming a cluster and/or network, whereby the describedfunctionality of the manipulating switch 41 may refer to thefunctionality accomplished by a part or the whole of the cluster and/ornetwork. In one embodiment, after source device 16 starts transmittingto display device 21, display device 22 may only access devices 13, 14,and 17. But the available bandwidth of the multi-stream channelsupporting HDMI-CEC 41 c decreases and therefore the multi-streammanipulating switch 41 has to make sure that future transmissions fromsource device 17 will be limited to the available bandwidth of 41 c. Thethroughput from source device 17 may be limited, for example, byimplementing the following method:

Multi-stream manipulating switch 42 removes the HPD signal to sourcedevice 17;

Then source device 17 initiates a read EDID transaction;

Multi-stream manipulating switch 42 replies the read EDID transactionwith a prefetched, manipulated, EDID of display device 22, such thatonly video formats that match the available bandwidth of themulti-stream channel 41 c are exposed to source device 17.

FIG. 4 illustrates an embodiment where display box 30 includes amulti-stream manipulating switch 31 outputting two standard HDMI outputsignals through ports 11 a and 11 b to the display device 11.Multi-stream manipulating switch 31 communicates with multi-streammanipulating switch 42 through a multi-stream channel supportingHDMI-CEC 31 c. Multi-stream manipulating switch 42 communicates with thesource devices (16, 17) through standard HDMI-CEC interface (32 a, 32b). When none of the source devices is active, and assuming that the CECbuses of ports 11 a and 11 b are not physically connected, the sourcedevices (13, 14, 16, 17) are visible to the display device 11 in one ortwo HDMI-CEC network views (because display device 11 has only twoHDMI-CEC inputs, 11 a and 11 b, it cannot have more than two HDMI-CECnetwork views).

After source device 16 is activated through port 11 a, and becausechannel 31 c is a multi-stream channel supporting HDMI-CEC, it is stillpossible to communicate with source device 17 through port 1 b.Therefore, multi-stream manipulating switch 31 manipulates the HDMI-CECnetwork view such that source devices 13, 14, and 17 appear to be in theHDMI-CEC network view of port 11 b, and therefore HDMI-CEC displaydevice 11 is still able to communicate with one of the remaining sourcedevices (13, 14, and 17).

When initializing the two HDMI-CEC network views of ports 11 a and 11 b,multi-stream manipulating switch 31 may place the source devices 16 and17 under the same HDMI-CEC network view or under different HDMI-CECnetwork views. Optionally, when channel 31 c is a multi-stream channelsupporting HDMI-CEC, the multi-stream manipulating switch 31 maymanipulate the HDMI-CEC network views as needed and locate sourcedevices 16 and 17 to be in the HDMI-CEC network view of port 11 a or inthe HDMI-CEC network view of port 11 b.

In one embodiment, after source device 16 starts transmitting to port 11a, source device 17 is manipulated by multi-stream manipulating switch31 to be in the HDMI-CEC network view of port 11 b. But the availablebandwidth of the multi-stream channel supporting HDMI-CEC 31 c decreasesand therefore the multi-stream manipulating switch 31 has to make surethat future transmissions from source device 17 will be limited to theavailable bandwidth of the multi-stream channel supporting HDMI-CEC 31c. The throughput from source device 17 may be limited, for example, byimplementing the following method:

Multi-stream manipulating switch 42 removes and restores the HPD signalto source device 17, in order to cause source 17 to read the EDID;

Then source device 17 initiates a read EDID transaction; and then

Multi-stream manipulating switch 42 replies the read EDID transactionwith a prefetched, manipulated, EDID of display device 11 such that onlyvideo formats that match the available bandwidth of the multi-streamchannel supporting HDMI-CEC 31 c are exposed to source device 17. Forexample, assuming link 31 c is a multi-stream channel supportingHDMI-CEC that is capable of transporting a total throughput of 8 Gbps,which is suitable for transmitting 1080 p, 60 Hz, 48 bit per pixel(bpp); If source device 16 transmits 1080 p 60 Hz 24 bpp to port 11 a,the multi-stream channel supporting HDMI-CEC 31 c still has enoughbandwidth to transmit another 1080 p 60 Hz 24 bpp stream. Assumingdisplay device 11 EDID indicates it can support 1080 p 60 Hz 36 bpp,then if source device 17 tries to transmit this kind of video format,the multi-stream channel supporting HDMI-CEC 31 c will not have enoughcapacity. Therefore, multi-stream manipulating switch 42 removes andrestores the HPD signal to source device 17, so that source 17 reads themanipulated EDID of display device 11, such that no other formatsrequiring higher bandwidth than the available bandwidth seem to besupported by port 11 b.

In another example, it is required to ensure in advance that there isenough bandwidth for a predefined number of source devices capable oftransmitting over a multi-stream channel supporting HDMI-CEC. In thiscase, before the first source device starts transmitting, the EDID ofthe appropriate display device is manipulated such that the totalmaximum bandwidth consumed by the predefined number of the sourcedevices communicating in parallel through the multi-stream channelsupporting HDMI-CEC is supported by the multi-stream channel. Forexample, if 31 c is a multi-stream channel supporting HDMI-CEC capableof transmitting a total throughput of 8 Gbps, each of source devices 16and 17 will be supplied with formats having a throughput that is equalto or lower than 1080 p 60 Hz 24 bpp stream.

Multi-Stream Daisy Chain Supporting HDMI-CEC.

FIG. 5A illustrates a multi-stream sub network within a multi-displaynetwork supporting HDMI-CEC having a multi-stream daisy chain includingsource devices supporting multi-stream 52, and 53, and source device 54,connected through the multi-stream channels supporting HDMI-CEC 51 a and52 a to the multi-stream manipulating switch 51, that is connected todisplay devices 55, 56, and 57. In this embodiment, the multi-streammanipulating switch 51 and each of the source devices supportingmulti-stream (52, 53) have to calculate their upstream residuebandwidth, and then expose only the video formats that match theavailable bandwidth of the chain's bottleneck.

For example, multi-stream channels supporting HDMI-CEC 51 a and 52 ahave a maximum throughput of 8 Gbps each. Assuming display device 56requests from source device supporting multi-stream 52 to starttransmitting a 6 Gbps stream over the multi-stream channel supportingHDMI-CEC 51 a, then the multi-stream channel supporting HDMI-CEC 51 ahas a residue bandwidth of 2 Gbps. Therefore, source device supportingmulti-stream 52 transmits to source device supporting multi-stream 53 amessage informing it that the residue bandwidth is 2 Gbps. In oneembodiment, the multi-stream channel supporting HDMI-CEC includes aninternal control channel between its nodes. Optionally, device 52utilizes the internal control channel for transmitting to device 53 themessage informing that the residue bandwidth is 2 Gbps. Thereafter,assuming display device 57 requests from source device 54 to starttransmitting, then source device supporting multi-stream 53 removes andrestores the HPD signal to source device 54, in order to make it readthe EDID of a virtual display device supporting up to 2 Gbps.

FIG. 5B illustrates one embodiment of a source device supportingmulti-stream 53, including: (i) an HDMI input port 53 a, (ii) a datasource 58 a, and (iii) a multi-stream manipulating switch 58 b havingtwo HDMI inputs ports and one multi-stream channel supporting HDMI-CEC52 a output. Optionally, the source device supporting multi-stream 53 iscapable of utilizing the multi-stream channel supporting HDMI-CEC 52 afor data received from the data source 58 a, or data received from theHDMI input port 53 a, or for data received from both inputs.

FIG. 5C illustrates one embodiment of a source device supportingmulti-stream 52, including: (i) an input for receiving a multi-streamchannel supporting HDMI-CEC 52 a, (ii) a data source 58 c, and (iii) amulti-stream manipulating switch 58 d having one HDMI stream input, onemulti-stream channel supporting HDMI-CEC input, and one multi-streamchannel supporting HDMI-CEC 51 a output. Optionally, the source devicesupporting multi-stream 52 is capable of utilizing the multi-streamchannel supporting HDMI-CEC 51 a for data received from the data source58 c, or data received from the multi-stream channel supporting HDMI-CEC52 a, or for data received from both inputs.

FIGS. 5D-5E illustrate one embodiment wherein the multi-streammanipulating switch 552 a is located within a display device 552. Themulti-stream manipulating switch 552 a includes logic which enables aplurality of HDMI-CEC display devices (552, 56) to control an HDMI-CECcluster tree, comprising a standard HDMI-CEC source 54 and a sourcedevice supporting multi-stream 53. The embodiment illustrated by FIG. 5Denables a user to connect a chain of source devices (linked using atleast one multi-stream channel supporting HDMI-CEC) to a chain ofdisplay devices, such that when none of the source devices is active,each display device may control all of the source devices, and when afirst display device communicates with a first source device usingHDMI-CEC, a second display device can still communicate with the othersource devices using HDMI-CEC.

Methods for Implementing a Multi-Stream Link.

A multi-stream manipulating switch may be connected to a multi-streamchannel supporting CEC. The multi-stream channel supporting HDMI-CEC maybe implemented using any appropriate technique, as long as thetransmitted streams are HDMI-CEC compatible. A multi-stream channelsupporting HDMI-CEC may be created using solutions for transmittingHDMI-CEC signals over media such as twisted-pair cables, coax cables,optical fibers, and/or implemented using a wireless solution.

Some examples of methods and systems suitable for HDMI-CEC compatibletransmissions over a twisted pair cable are available in U.S. patentapplication Ser. No. 11/703,080, filed on Feb. 7, 2007, which isincorporated herein by reference in its entirety for all that it teacheswithout exclusion of any part thereof.

Some examples of methods and systems suitable for HDMI-CEC compatibletransmissions over optical fibers are available in US patent applicationpublication number US20070233906, which is incorporated herein byreference in its entirety for all that it teaches without exclusion ofany part thereof.

Some examples of methods and systems suitable for HDMI-CEC compatibletransmissions through wireless communication are available in PCT patentapplication publication number WO/2006/101801, which is incorporatedherein by reference in its entirety for all that it teaches withoutexclusion of any part thereof.

Examples of Basic CEC Manipulation Functions

In one embodiment, the manipulating switch utilizes one or more of thefollowing four CEC manipulation functions.

1) CEC Propagation Control.

The CEC propagation control function enables the manipulating switch toreceive a CEC block which was initiated by a certain device; and pass orintercept the received CEC block to a certain device(s), optionally onthe fly, and without modifying the received block. For example, themanipulating switch may divide the HDMI-CEC cluster tree into multipleHDMI-CEC cluster trees and may control the propagation of the CEC blocksbetween the multiple HDMI-CEC cluster trees; the multiple HDMI-CECcluster trees may partially overlap.

Referring to FIG. 6A, assume that manipulating switch 64 controls twoHDMI-CEC cluster trees. The first HDMI-CEC cluster tree includes sourcedevices 66 and 67 and display device 62. The second HDMI-CEC clustertree includes source devices 65, 66 and 67 and display device 61.Utilizing the CEC propagation control function, the manipulating switch64 controls the propagation of CEC blocks within each of the HDMI-CECcluster trees and the propagation of CEC blocks between the variousHDMI-CEC cluster trees. This means that the manipulating switch mayforward certain CEC blocks to some source or display devices and notforward the certain CEC blocks to other source or display devices it isconnected to.

FIG. 17 is a flow diagram illustrating one method comprising thefollowing steps: In step 170, receiving a CEC block which was initiatedby a first HDMI-CEC device. In step 171, passing the received CEC blockto a second HDMI-CEC device. And in step 172, preventing a thirdHDMI-CEC device from receiving the CEC block FIG. 18 is a flow diagramillustrating one method comprising the following steps: In step 180,dividing a plurality of devices into at least a first HDMI-CEC clustertree coupled to a first display device, and a second HDMI-CEC clustertree coupled to a second display device, wherein the HDMI-CEC clustertrees partially overlap. In step 181, receiving a first CEC block whichwas initiated by the first HDMI-CEC cluster tree. In step 182, passingthe first CEC block to the first display device not passing the firstCEC block to the second display device.

2) CEC on the Fly Modification.

The CEC on the fly modification function enables the manipulating switchto: (i) receive a CEC block which was initiated by a certain device,(ii) modify one or more bits in the received CEC block, optionally onthe fly, and (iii) supply the modified CEC block to a certain device(s).

For example, a source device is associated with two HDMI-CEC networkviews through a manipulating switch, and the source device holdsdifferent logical addresses for each HDMI-CEC network view. When adisplay device, associated with the first HDMI-CEC network view,transmits a CEC message to the source device, that stores a logicaladdress matching the second HDMI-CEC network view, the manipulatingswitch may replace the CEC destination address with the address matchingthe second HDMI-CEC network view, such that the source device willidentify the CEC message as addressed to it. When, or immediately after,the manipulating switch receives the CEC block containing the four bitsof source address and the four bits of destination address, it candetermine whether the block was correctly or incorrectly modified. Ifthe block was incorrectly modified, the manipulating switch drops theCEC message, optionally by changing one or more of the address bits orusing a <feature abort> message. On the fly modification may also beapplied to downstream CEC messages (e.g. from the source device to thedisplay device). In this case, the source device transmits a CEC messageusing the logical addresses it stores. Then, the manipulating switch maymodify the source and/or destination addresses according to addressesmatching the recipient's HDMI-CEC network view.

As explained in the HDMI spec 1.3, a transaction on a CEC line involvesan initiator and one or more followers. The initiator is responsible forsending the message structure and the data (sometimes both of themreferred to herein as data). The follower is the recipient of the dataand is responsible for setting any acknowledgement bits.

FIG. 19 is a flow diagram illustrating one method comprising thefollowing steps:

In step 190, receiving a CEC message from a first HDMI-CEC port, the CECmessage comprising data according to the initiator's HDMI-CEC networkview. In step 191, modifying the CEC data, approximately on the fly, tomatch the follower's HDMI-CEC network view. Optionally, the data isselected from the group of CEC source logical address, or CECdestination logical address, or CEC source logical address and CECdestination logical address. And in step 192, transmitting the modifiedCEC message through a second HDMI-CEC port.

3) CEC Block Termination.

The CEC block termination function enables the manipulating switch toreceive a CEC block which was initiated by a certain device; optionallyacknowledge (ACK) the block; modify the received block; and supply themodified blocks to a certain device(s). Optionally, a few blocks or allthe blocks comprising the CEC may be partially or completely modified.Alternatively, only a section of the block may be modified, for example,only the header containing the logical addresses may be modified.

In one embodiment, although the manipulating switch modifies thereceived block, the source address still matches the source address ofthe original initiator of the block and not the source address of themanipulating switch.

In one embodiment, a transmission is stopped using CEC Line ErrorHandling, such as defined in HDMI spec 1.3 paragraph CEC 7.4. CEC lineerror handling enables a device acting as follower to notify all otherdevices (primarily the initiator) that a potential error has occurred,where an error is defined as a period between falling edges that isshorter than a minimum data bit period.

FIG. 20 is a flow diagram illustrating one method comprising thefollowing steps: In step 200, receiving a CEC block through a firstHDMI-CEC port and in step 201, acknowledging the CEC block. In step 202modifying one or more bits in the received CEC block. And in step 203,sending the modified CEC block through at least a second HDMI-CEC port.

FIG. 21 is a flow diagram illustrating one method comprising thefollowing steps: In step 210, receiving a CEC block comprising adestination logical address matching the initiator's HDMI-CEC networkview. In step 211, acknowledging the CEC block. In step 212, modifyingthe destination logical address to match the follower's HDMI-CEC networkview. And in optional step 213, forwarding the modified block to thefollower.

4) CEC Message Generation.

The CEC message generation function enables the manipulating switch toself generate one or more CEC blocks or one or more CEC messages, andsupply the generated CEC message to a certain device(s). Optionally, theself generated CEC message is not initiated directly by a CEC messagereceived by the manipulating switch. For example, the manipulatingswitch may generate a CEC message in order to perform one or more of thefollowing: create an HDMI-CEC network view for a device, emulate a CECmessage from a device, assign physical address to a CEC device, or spoofthe HDMI-CEC cluster tree. By learning the HDMI network, themanipulating switch may create spoofed CEC transactions and/or spoof theaddress allocation process.

For example, referring again to FIG. 6A as an illustration of anHDMI-CEC network with two display devices 61 and 62, display device 61may be accessed by all source devices in the network and display device62 may be accessed only by source devices 66 and 67. While displaydevice 61 retrieves its HDMI-CEC network view using the normal HDMI-CECprocedure, manipulating switch 64 prevents display device 62 fromreceiving the CEC transactions used for creating the HDMI-CEC networkview exposed to display device 61, optionally using the CEC propagationcontrol function. During that process, manipulating switch 64 may learnthe HDMI-CEC network topology and create spoofed CEC transactions usedfor creating the HDMI-CEC network view exposed to display device 62,optionally using the CEC message generation function.

As another example, the manipulating switch may create an appropriateHDMI-CEC network view for each downstream and/or upstream path. In oneembodiment, the manipulating switch creates the appropriate HDMI-CECnetwork view by spoofing CEC transactions using the CEC <report physicaladdress> message that causes the addressed CEC device to report, to theother CEC devices in the HDMI-CEC cluster tree, the connection betweenits HDMI physical address and its CEC logical address.

In one example, FIGS. 6A-C illustrate manipulating switch 64 spoofingthe CEC transactions for display device 62, optionally using the CEC“report physical address” message. In this example, display device 61receives an HDMI-CEC network view as if it were the only display deviceconnected to the HDMI-CEC cluster tree, while display device 62 alsoreceives an HDMI-CEC network view as if it were the only display deviceconnected to the HDMI-CEC cluster tree.

FIG. 6B illustrates the HDMI-CEC network view of display device 61,where the physical addresses are denoted by a four digit number and thelogical addresses are denoted inside brackets. The manipulating switch64 makes sure that the various source devices receive the right physicaladdresses using the HDMI EDID distribution process with the EDID ofdisplay device 61. After retrieving its physical address, each sourcedevice may assign itself a CEC logical address as known in the art.Then, each source device reports the connection between its logical andphysical addresses using the <report physical address> CEC message. Inthe HDMI-CEC network view of display device 61 illustrated by FIG. 6B,switch 63 receives the physical address 1.0.0.0, DVD 65 receives thephysical address 1.1.0.0 and the logical address 4, switch 64 receivesthe physical address 1.2.0.0, STB 66 receives the physical address1.2.1.0 and the logical address 3, and game console 67 receives thephysical address 1.2.2.0 and the logical address 8.

FIG. 6C illustrates the spoofed HDMI-CEC network view of display device62, where the physical addresses are denoted by a four digit number andthe logical addresses are denoted inside brackets. HDMI-CEC does notsupport a multiple display architecture, therefore, the manipulatingswitch 64 spoofs the HDMI-CEC network view of display device 61 by selfgenerating the appropriate CEC blocks that are supposed to be receivedand transmitted by source devices 66 and 67. In the HDMI-CEC networkview of display device 62 illustrated by FIG. 6C, switch 64 receives thephysical address 1.0.0.0, STB 66 receives the physical address 1.1.0.0and the logical address 3, and game console 67 receives the physicaladdress 1.2.0.0 and the logical address 8.

In one embodiment, the manipulating switch tries to maintain the samephysical address and/or logical address assigned to each device in eachof the HDMI-CEC network views. For example, source devices 66 and 67 inFIGS. 6B and 6C have the same logical addresses.

Examples of CEC Manipulation Operations

In some embodiments, one or more of the four basic CEC manipulationfunctions described above are used for the following CEC manipulationoperations.

Manipulating The HDMI-CEC Network View.

In one embodiment, the manipulating switch manipulates the activesources existing in the HDMI-CEC network view of each display device.FIG. 7 illustrates a case where display device 61 receives data fromsource device 73. Because HDMI link 64 a can carry only one stream,manipulating switch 64 has to disconnect the entire HDMI-CEC clustertree connected by HDMI link 64 a from the HDMI-CEC network view ofdisplay device 62. In other words, the HDMI-CEC network view of displaydevice 62 is manipulated according to the source-display stream activityand network topology.

In one embodiment, when a source device starts transmitting to a firstdisplay device, the manipulating switch may change the physicaladdresses of the rest of the network such that the rest of the networkwill be ready to transmit to the second display device. Alternatively,when a source device starts transmitting to a first display device,updating the physical addresses of the specific source device and itsdownstream devices is sufficient and there is no need to update theentire network regarding the change in the physical address of theactive source device.

FIG. 22 is a flow diagram illustrating one method for discovering theCEC logical addresses of HDMI-CEC devices coupled to at least twoHDMI-CEC ports of a manipulating switch, the method comprisingperforming the following steps for each HDMI-CEC port: In step 220,generating CEC messages, wherein the generated CEC messages areoptionally CEC polling messages. In step 221, transmitting the generatedCEC messages through the HDMI-CEC port. In step 222, receiving repliesto the transmitted CEC messages. In step 223, not transmitting thereceived replies through the other HDMI-CEC ports. In step 224,determining the CEC logical addresses of the HDMI-CEC devices coupled tothe HDMI-CEC port from the received replies. And in optional step 225,discovering the physical addresses of the HDMI-CEC devices coupled tothe HDMI-CEC ports using CEC <Give Physical Address> messages.

In one embodiment, the following method steps are performed:Maintaining, by a manipulating switch, a first HDMI-CEC network view ofa first HDMI-CEC display device and a second HDMI-CEC network view of asecond HDMI-CEC display device, wherein the first and the secondHDMI-CEC network views comprise a first HDMI-CEC source device that iscommon to both HDMI-CEC network views, whereby the common device definesthe overlapping HDMI-CEC cluster tree. And approximately while there isTMDS communication between the first HDMI-CEC source device and thefirst HDMI-CEC display device, disconnecting the HDMI-CEC sub clustertree associated with a first HDMI-CEC input port of the manipulatingswitch, which comprises the first HDMI-CEC source device, from theHDMI-CEC devices located in a second non-overlapping HDMI-CEC clustertree. Optionally, the step of disconnecting the HDMI-CEC sub clustertree may occur approximately when identifying one or more of thefollowing CEC messages: <set stream path>, <active source>, <image viewon>, or <text view on>.

Assigning The Same Physical Addresses to Different HDMI-CEC ClusterTrees.

In one embodiment, CEC propagation control is used with CEC broadcastmessages, such as “report physical address”, and when at least twosubsets of at least two overlapping or partially overlapping HDMI-CECnetwork views share the same physical and logical addresses or share thesame logical addresses. Therefore, the manipulating switch tries tocreate a situation where the same device holds the same physical andlogical addresses, or just the same logical address, in two or moreHDMI-CEC network views.

Referring to FIG. 7 as an example, the manipulating switch 64 mayidentify the more complicated physical address tree of the two HDMI-CECcluster trees, optionally by comparing the physical address received inthe HDMI output port connected to 63 b with the physical addressreceived in the HDMI output port connected to 62 a. Then themanipulating switch assigns its upstream devices physical addressesmeeting the more complicated physical address tree. In the example ofFIG. 7 the more complicated physical address tree is the HDMI-CECcluster tree of display device 61. Then the manipulating switchgenerates spoofed report physical address CEC messages that aretransferred to the less complicated physical address tree, which is theHDMI-CEC cluster tree of display device 62 in the example of FIG. 7. Themanipulating switch 64 may create the HDMI-CEC network view of displaydevice 62 by generating “report physical address” CEC messages that aretransferred to the display device 62.

In one embodiment, a method for assigning a required physical address toan HDMI-CEC device, comprising: determining by a manipulating switch therequired HDMI physical address to be assigned to an upstream HDMI-CECdevice, and providing the required HDMI physical address to the upstreamHDMI-CEC device. Wherein the required HDMI physical address is differentfrom the true HDMI physical address that should have been assignedaccording to the standard HDMI procedure for computing an HDMI physicaladdress.

In one embodiment, a method operating a network comprising at least twoHDMI-CEC display devices with their associated at least two HDMI-CECcluster trees that at least partially overlap, comprising: identifying aset of HDMI physical addresses to be assigned to the HDMI-CEC devices inat least one upstream HDMI-CEC sub cluster tree of a manipulatingswitch, whereby these HDMI physical addresses will be consistent in theHDMI-CEC network views of the first and the second HDMI-CEC displaydevices.

Manipulating The Logical Address of a Device in The HDMI-CEC ClusterTree.

The logical address of a device describes the device's functionality.The HDMI-CEC cluster tree is limited in the total number of devices itcan contain (for example up to 10 devices) and in the number of devicesof the same type it can contain (for example one audio system and fourtuners). For example, section “CEC 10.2 Logical Addressing” in the HDMIspecification version 1.3a describes the available logical addresses.

Referring again to FIG. 7, assuming source devices 65, 72, 73, and 74are playback devices, but the HDMI-CEC cluster tree supports only up to3 playback devices. Therefore, display device 61 should see only threesource devices, while display device 62, which cannot receive streamsfrom source device 65 (because HDMI link 63 b is asymmetric), should seeall the three source devices from which it can receive streams (72, 73,74). Assuming source device 72 is disconnected from the HDMI-CEC clustertree, source devices 65, 73 and 74 are visible to display device 61,while only source devices 73 and 74 are visible to display device 62.When source device 72 is connected to the HDMI-CEC cluster tree,manipulating switch 64 sees source devices 73, 74 and 72, but theHDMI-CEC network view of display device 61 cannot include 4 playbackdevices in a standard HDMI-CEC cluster tree and this may be solved byone of the following two non-limiting examples.

A first example of assigning a valid logical address includes thefollowing steps:

Playback device 72 wakes up and because HDMI-CEC cluster tree of displaydevice 61 already contains three playback devices, playback device 72cannot allocate a playback device CEC logical address.

While playback device 72 tries to receive its appropriate logicaladdress, the other sources identify themselves, and as a result themanipulating switch 64 holds an updated network topology of the sourcedevices having the same function.

Then manipulating switch 64 checks if it is possible to assign toplayback device 72 a logical address in the HDMI-CEC cluster tree ofdisplay device 62, so that the HDMI-CEC network view of display device62 will include playback device 72 with its true logical address. Thismay be possible because source device 65 is under switch 63 andtherefore is not accessible by display device 62.

If it is possible, the manipulating switch 64 causes playback device 72to reinitialize itself using the HPD signal, and then the manipulatingswitch 64 emulates the entire HDMI-CEC cluster tree of display device 62in order for playback device 72 to receive the appropriate logicaladdress. One example of an address allocation process includes thefollowing steps: playback device 72 attempts to acquire a logicaladdress by sending polling message to that address, and the manipulatingswitch 64 generates an answer for the logical addresses it does not wantplayback device 72 to acquire.

After source device 72 receives its appropriate logical address, themanipulating switch 64 may emulate source device 72 in order to notifydisplay device 62 of the logical address of source device 72.

A second example of assigning a valid logical address includes thefollowing steps:

Still referring to FIG. 7, manipulating switch 64 creates for itself thedownstream HDMI-CEC network view through his HDMI outputs, andcalculates the logical addresses it should assign to the upstreamdevices (72, 73, and 74).

Source device 72 wakes up as an HDMI-CEC device and the manipulatingswitch 64 assigns to source device 72 an address according to itspreferences, by emulating the entire HDMI-CEC cluster tree.

Then the manipulating switch 64 checks whether a downstream devicealready owns the address assigned to source device 72. If a downstreamdevice already owns the address, manipulating switch 64 repeats theprocess so that source device 72 will receive a different address.

FIG. 8 illustrates a network example where a maximum number of 3playback devices (having CEC logical addresses 8, 9, and 11) is allowedand already assigned to playback devices 81, 82, and 83. When playbackdevice 84 connects to the network, the manipulating switch 64 has noavailable playback device logical address that is valid for bothHDMI-CEC cluster trees. Therefore, the manipulating switch 64 assignsplayback device 84 a logical address that meets one of the HDMI-CECcluster trees and spoofs the other HDMI-CEC cluster tree. For example,manipulating switch 64 may actually assign the logical address 9 toplayback device 84, which is accepted by the HDMI-CEC network view ofdisplay device 61, and spoof the HDMI-CEC network view of display device62 to believe that playback device 84 holds the logical address 8.

FIG. 24 is a flow diagram illustrating one method for assigning arequired CEC logical address to an HDMI-CEC source device, comprisingthe following steps: In step 240, determining the required CEC logicaladdress to be acquired by the HDMI-CEC source device. In step 241,reinitializing the HDMI-CEC source device to acquire a CEC logicaladdress utilizing polling messages. And in step 242, spoofing theacknowledgements to polling messages containing CEC logical addressesother than the required CEC logical address.

FIG. 23 is a flow diagram illustrating one method comprising thefollowing steps: In step 230, dividing, by a manipulating switch, aplurality of HDMI-CEC devices into at least a first HDMI-CEC clustertree coupled to a first HDMI-CEC display device, and a second HDMI-CECcluster tree coupled to a second HDMI-CEC display device, wherein theHDMI-CEC cluster trees partially overlap. In step 231, determining afirst and a second HDMI-CEC network view for the first and the secondHDMI-CEC display devices, whereby the two HDMI-CEC network viewspartially overlap. And in step 232, enabling a second HDMI-CEC sourcedevice in the second HDMI-CEC cluster tree to acquire a required CEClogical address already in use by a first HDMI-CEC source device in thefirst HDMI-CEC cluster tree, wherein the first and the second HDMI-CECsource devices are located in the non-overlapping parts of the HDMI-CECnetwork views.

Assigning The Correct EDID To an Active Source.

In one embodiment, if a first display device sends a CEC <set streampath> message to a source device but the source device does not storethe correct EDID of the first display device, the manipulating switchemulates the HDMI-CEC cluster tree in order to cause the active sourcedevice to have the correct EDID of the first display device. Themanipulating switch is capable of knowing the correct EDID of the firstdisplay device using the 12 c interface. Moreover, if the physicaladdress assigned to the source device does not meet the HDMI-CEC networkview of the first display device, the manipulating switch may alsoemulate the HDMI-CEC cluster tree in order to cause the active sourcedevice to have the required physical address.

Elimination of a Hierarchic Level in an HDMI-CEC network view.

HDMI limits the network view to include up to 4 hierarchic levels. Inone embodiment, the manipulating switch eliminates one or morehierarchic levels from the HDMI-CEC network view of a display device.FIG. 9 illustrates an example where the HDMI-CEC network views of bothdisplay devices 61 and 62 include 5 hierarchic levels. In order to beable to approach and control source device 94 using CEC, themanipulating switch 64 may eliminate, for example, the existence ofswitch 71 from the HDMI-CEC network views of display devices 61 and 62.FIG. 9 illustrates a case where the manipulating switch 64 spoofs thephysical addresses of its upstream and downstream devices. As a resultof implementing the physical address spoofing of eliminating theexistence of switch 71, the HDMI-CEC network views of both displaydevices 61 and 62 include no more than 4 hierarchic levels. As a resultof implementing the physical address spoofing of eliminating thedownstream devices of the manipulating switch 64, it is possible tocontrol devices 71, 72, 73, 74, and 94 using CEC. It is to be understoodthat the described physical address spoofing method may be implementedon many more hierarchic levels, utilizing more manipulating switches.Moreover, the manipulating switch may always try to eliminatehierarchical levels in order to enable as many hierarchical levels aspossible.

In one embodiment, the manipulating switch uses polling messages toverify, maintain and/or discover the CEC logical addresses of thenetwork devices. The manipulating switch may check the logicaladdress(es) from time to time in order to make sure that it stores anupdated view of the network.

When the manipulating switch receives a polling message it knows whetherit should answer with an ACK or not according to the stored HDMI-CECnetwork view(s). Referring again to FIG. 8, assume that the manipulatingswitch 64 receives a polling message from display device 62 containingthe logical address of source device 73 in the HDMI-CEC network view ofdisplay device 62. The manipulating switch replies with an ACK and doesnot forward the original message to source device 73 because it actuallyholds a different logical address in accordance with the HDMI-CECnetwork view of display device 61. If needed, the manipulating switchmay transmit to source device 73 a modified polling message containingits actual address. Similarly, the manipulating switch 64 may processpolling messages from an upstream device to a downstream device. Forexample, a polling message from source device 73 containing the logicaladdress of playback device 83 in the HDMI-CEC network view of displaydevice 62 may be forwarded through HDMI link 62 a if the message'saddress meets the actual address. Alternatively, the manipulating switchreplies with an ACK and does not forward the original message toplayback device 83. If needed, the manipulating switch may transmit toplayback device 83 a modified polling message containing its actualaddress.

FIG. 14 is a flow diagram illustrating one method for emulating anHDMI-CEC sub network, comprising the following steps: In step 140,determining the properties of the HDMI-CEC sub network. In step 141,generating CEC messages that emulate the CEC messages initiated by theHDMI-CEC sub network. And in step 142, answering CEC messages addressedto the emulated HDMI-CEC sub network.

FIG. 25 is a flow diagram illustrating one method for manipulatingHDMI-CEC messages transmitted over a network comprising at least a firstand a second HDMI-CEC display device with their associated first andsecond HDMI-CEC cluster trees that at least partially overlap, themethod comprising the following steps: In step 250, monitoring the CEC<Report Physical Address> messages resulting from the physical addressdiscovery process of the first and the second HDMI-CEC cluster trees. Instep 251, preventing the non-overlapping section of the second HDMI-CECcluster tree from receiving the CEC messages initiated by the firstHDMI-CEC cluster tree, and preventing the first HDMI-CEC cluster treefrom receiving the CEC messages initiated by the non-overlapping sectionof the second HDMI-CEC cluster tree. In step 252, preventing propagationof EDID associated with the non-overlapping section of the HDMI-CECcluster tree to the first HDMI-CEC cluster tree. In step 253, utilizingthe CEC <Report Physical Address> messages resulting from the physicaladdress discovery process of the first and the second HDMI-CEC clustertrees for learning the first and the second HDMI-CEC network views. Instep 254, spoofing CEC <Report Physical Address> messages from theoverlapping section of the HDMI-CEC cluster tree towards thenon-overlapping section of the second HDMI-CEC cluster tree. And inoptional step 255, determining the preferred physical and logicaladdresses to be acquired by the HDMI-CEC devices in the overlappingsection of the HDMI-CEC cluster tree.

In one embodiment, when a message sender transmits a CEC message to amessage recipient, the manipulating switch may intercept one or more ofthe CEC blocks, and answer with an ACK (the message may be directeddownstream or upstream). Then the manipulating switch may transmit anappropriately modified or generated CEC blocks to the message recipient.If the message recipient does not accept the message or cannot performthe request, the manipulating switch may transmit a <feature abort>message to notify the message sender of the failure to execute themessage.

Symmetric Channel

FIG. 11A illustrates a symmetric communication channel 112 connectingbetween the manipulating switches 114 and 116. If the symmetriccommunication channel 112 was a unidirectional communication channel andnot a symmetric communication channel, display device 61 may have hadaccess to source devices 65 and 66, while display device 62 may have hadaccess only to source device 66. As a result of using the symmetriccommunication channel 112, display device 62 may also access sourcedevice 65. In the illustrated embodiment, the symmetric communicationchannel 112 does not influence the HDMI-CEC network view of displaydevice 61. FIG. 11B illustrates the physical addresses allocated to theHDMI-CEC network view of display device 61. As illustrated, manipulatingswitch 114 may have manipulating switch 116 and source device 65 as itsupstream devices. Therefore, manipulating switch 114 receives thephysical address of (1.0.0.0), manipulating switch 116 receives thephysical address of (1.1.0.0), source device 65 receives the physicaladdress of (1.1.1.0), and source device 66 receives the physical addressof (1.2.0.0).

It is to be understood that the symmetric channel may also be amulti-stream symmetric channel. A multi-stream symmetric channel mayutilize the above described methods and devices for utilizing amulti-stream channel within an HDMI-CEC cluster trees, operating amulti-stream manipulating switch, calculating the residue bandwidth,ensuring enough bandwidth in advance, and/or operating a multi-streamdaisy chain supporting HDMI-CEC.

Non-HDMI Cables

There are solutions for transmitting HDMI-CEC over non-standard HDMIcables, such as CAT5x, CAT6, coax, or fiber, wirelessly, or using anyother solution that may be available today as well as in the future. Theembodiments of the manipulating switch cover all of these alternativesolutions and all of the alternative multimedia interfaces. For example,in FIG. 2, connection 12 a may be an HDMI cable while connection 12 bmay be an optical fiber, 12 c may be a CAT6 cable, 15 a may be a coaxcable, and 15 b may be a wireless link. In other words, the variousdisclosed embodiments are not limited to some specific HDMI cable butmay be implemented using any appropriate communication medium.

FIG. 10 illustrates a manipulating switch 180 having an HDMI cable input183 that may be connected to an HDMI source device, a CAT5e input 184that may be connected to an HDMI source device over a twisted pairsystem, wireless output 181 that may communicate with an HDMI displaydevice over a wireless system and coax output 182 that may be connectedto an HDMI display device over coax cable system.

Although the embodiments have been described in considerable detail withreference to certain embodiments thereof, other embodiments arepossible.

Certain features of the embodiments, which may, for clarity, bedescribed in the context of separate embodiments, may also be providedin various combinations in a single embodiment. Conversely, variousfeatures of the embodiments, which may, for brevity, be described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination.

The embodiments are not limited in their applications to the details ofthe order or sequence of steps of operation of methods, or to details ofimplementation of devices, set in the description, drawings, orexamples.

While the methods disclosed herein have been described and shown withreference to particular steps performed in a particular order, it willbe understood that these steps may be combined, sub-divided, orreordered to form an equivalent method without departing from theteachings of the embodiments. Accordingly, unless specifically indicatedherein, the order and grouping of the steps is not a limitation of theembodiments.

Any citation or identification of any reference in this applicationshall not be construed as an admission that such reference is availableas prior art to the embodiments of the present invention.

While the embodiments have been described in conjunction with specificexamples thereof, it is to be understood that they have been presentedby way of example, and not limitation. Moreover, it is evident that manyalternatives, modifications and variations will be apparent to thoseskilled in the art. Accordingly, it is intended to embrace all suchalternatives, modifications and variations that fall within the spiritand scope of the appended claims and their equivalents. In the claims,means-plus-function clauses are intended to cover the structuresdescribed herein as performing the recited function and not onlystructural equivalents, but also equivalent structures.

1. A method for operating a network coupled at least to a first HDMI-CECsource device, a second HDMI-CEC display device, and a third HDMI-CECdisplay device, the method comprising: dividing, by the networkincluding a manipulating switch, a plurality of devices partiallyoverlapped into at least a first HDMI-CEC cluster tree coupled to thesecond HDMI-CEC display device, and a second HDMI-CEC cluster treecoupled to the third HDMI-CEC display device; receiving, by the network,a CEC block which was initiated by the first HDMI-CEC source device;passing, by the network, the received CEC block to the second HDMI-CECdisplay device; preventing, by the network, the third HDMI-CEC displaydevice from receiving the CEC block, although the network is coupled tothe third HDMI-CEC device; and further comprising receiving a second CECblock by the network, modifying the second CEC block on the fly to anetwork view of the second HDMI-CEC cluster tree, and passing themodified CEC block to a fourth HDMI-CEC device associated with thesecond HDMI-CEC cluster tree.
 2. The method of claim 1, wherein thesteps of passing and preventing are performed on the fly and withoutmodifying the received CEC block.
 3. The method of claim 2, wherein thenetwork comprises a manipulating switch, and the steps of receiving,passing, and preventing refer to HDMI-CEC ports of the manipulatingswitch, and the first, second and the third HDMI-CEC devices are coupledto the HDMI-CEC ports of the manipulating switch.
 4. The method of claim2, wherein the step of receiving is implemented by a first HDMI-CECinput port coupled to the first HDMI-CEC device, and the step ofpreventing is also implemented by the HDMI-CEC input port coupled to thefirst HDMI-CEC device.
 5. The method of claim 1, wherein the modifiedCEC block comprises an address matching the network view of the fourthHDMI-CEC device.
 6. A method comprising: dividing, by a networkincluding a manipulating switch, a plurality of HDMI-CEC devices into atleast a first HDMI-CEC cluster tree coupled to a first display device,and a second HDMI-CEC cluster tree, wherein the first HDMI-CEC clustertree comprising a first HDMI-CEC display device, the second HDMI-CECcluster tree comprising a second display device, and the first HDMI-CECcluster tree and the second HDMI-CEC cluster tree are at least partiallyoverlap; receiving, by the network coupled to both the first HDMI-CECcluster tree and the second HDMI-CEC cluster tree, a first CEC blockwhich was initiated by the first HDMI-CEC cluster tree; passing, by thenetwork, the first CEC block to the first HDMI-CEC display device, andnot passing the first CEC block to the second HDMI-CEC display device,although the network is also coupled to the second HDMI-CEC displaydevice.
 7. The method of claim 6, wherein the network comprises amanipulating switch, and the steps of receiving, passing, and notpassing refer to HDMI-CEC ports of the manipulating switch, and thefirst and the second display devices are coupled to the HDMI-CEC portsof the manipulating switch.
 8. The method of claim 6, wherein the stepof receiving is implemented by a first port of a manipulating switchthat is coupled to the first HDMI-CEC cluster tree; and the step ofpassing is implemented by a second port of the manipulating switch thatis coupled to the second display device.
 9. The method of claim 6,wherein the step of passing the first CEC block is performed on the fly.10. The method of claim 9, further comprising passing the first CECblock without modifying the first CEC block.
 11. The method of claim 9,further comprising, receiving by the network a second CEC block, whichwas initiated by the first display device; and passing the second CECblock only to the first HDMI-CEC cluster tree.
 12. A device in anoverlapped HDMI-CEC cluster trees network of at least a first HDMI-CECcluster tree and a second HDMI-CEC cluster tree, comprising at least oneHDMI-CEC input port and at least two HDMI-CEC output ports; the deviceconfigured to control propagation of CEC messages between the at leastone HDMI-CEC input port and the at least two HDMI-CEC output ports basedon origin and target of the CEC messages; wherein the device is furtherconfigured to forward some of the CEC messages between some of theHDMI-CEC ports, and prevent some of the CEC messages from beingforwarded between some of the HDMI-CEC ports, although all the HDMI-CECports belong to the same device.
 13. The device of claim 12, wherein thedevice enables the operation of a network comprising at least oneHDMI-CEC source device, and at least two HDMI-CEC display devices,whereby each of the display devices communicates with the availableHDMI-CEC source devices using HDMI-CEC.
 14. A manipulating devicecoupled to a first HDMI-CEC source device, a second HDMI-CEC displaydevice, and third HDMI-CEC display device, the manipulating devicecomprising: means for dividing a network into at least a first HDMI-CECcluster tree including the second HDMI-CEC display device, and a secondHDMI-CEC cluster tree including the third HDMI-CEC display device,wherein the first HDMI-CEC cluster tree and the second HDMI-CEC clustertree partially overlap; means for receiving a CEC block which wasinitiated by the first HDMI-CEC source device; and means for passing thereceived CEC block to the second HDMI-CEC display device and preventingthe third HDMI-CEC device from receiving the CEC block, although thefirst HDMI-CEC source device, the second HDMI-CEC display device, andthe third HDMI-CEC display device are coupled to each other andconfigured to communicate using a standard CEC shared bus controller.15. The device of claim 14, wherein the means for passing and preventingoperate on the fly and do not modify the received CEC block.
 16. Thedevice of claim 14, wherein the means for passing and preventing referto HDMI-CEC ports of a manipulating switch, and the first and the secondHDMI-CEC devices are coupled to the HDMI-CEC ports.
 17. The device ofclaim 14, further comprising means for modifying the CEC block, on thefly, to match the HDMI-CEC network view of the second HDMI-CEC device.18. The device of claim 17, further comprising means for determiningwhether the modification was performed correctly, and means for droppingthe CEC message.
 19. The device of claim 18, wherein the means fordropping the CEC message comprises utilizing CEC line error.
 20. Thedevice of claim 14, wherein the second and third HDMI-CEC devices areHDMI-CEC display devices.
 21. The device of claim 20, wherein the firstHDMI-CEC device is an HDMI-CEC source device and the HDMI-CEC displaydevices control the HDMI-CEC source device using HDMI-CEC.